When you receive a call on loudspeaker mode, the design and functionality of your phone's hardware and software work together to prevent the caller from hearing their own voice as feedback. This is achieved through a feature called acoustic echo cancellation (AEC).
Acoustic echo cancellation is a signal processing technique implemented in smartphones and other audio devices. It is designed to eliminate or minimize echo caused by audio feedback loops. In the context of a phone call on loudspeaker mode, here's how it typically works:
Microphone and Speaker Placement: The microphone and speaker on your phone are positioned in a way that minimizes the possibility of audio feedback. The microphone is located away from the speaker, reducing the likelihood of picking up sound from the loudspeaker.
Noise and Echo Suppression: The phone's software employs algorithms to suppress noise and echoes during a call. This helps distinguish between the audio that is intended to be transmitted (your voice) and any unwanted echoes or background noise.
Echo Cancellation: Advanced echo cancellation algorithms are utilized to analyze the audio input from the microphone and identify any echoes that may be present. The system then subtracts or cancels out these echoes from the outgoing audio signal, preventing the caller from hearing their own voice as feedback.
By implementing these techniques, smartphones can effectively prevent the caller from experiencing feedback or hearing their own voice during a call on loudspeaker mode. However, it's worth noting that the effectiveness of echo cancellation can vary depending on the specific phone model and the quality of the hardware and software employed.